<div class="intro">

<p>This example shows how to create an asynchronous test with the YUI Test framework for testing browser-based JavaScript code.

A <code>Y.Test.Case</code> object is created with a test that waits for a

few seconds before continuing. The <code>Y.Test.Runner</code>

is then used to run the tests once the page has loaded.</p>

</div>

<div class="example yui3-skin-sam">

<style scoped>

#testLogger {

margin-bottom: 1em;

}

#testLogger .yui3-console .yui3-console-title {

border: 0 none;

color: #000;

font-size: 13px;

font-weight: bold;

margin: 0;

text-transform: none;

}

#testLogger .yui3-console .yui3-console-entry-meta {

margin: 0;

}

.yui3-skin-sam .yui3-console-entry-pass .yui3-console-entry-cat {

background: #070;

color: #fff;

}

</style>

{{>test-async-test-source}}

</div>

<h2 class="first">Asynchronous Test Example</h2>

<p>This example begins by creating a namespace:</p>

```

Y.namespace("example.test");

```

<p>This namespace serves as the core object upon which others will be added (to prevent creating global objects).</p>

<h3>Creating the TestCase</h3>

<p>The first step is to create a new <code>Y.Test.Case</code> object called <code>AsyncTestCase</code>.

To do so, using the <code>Y.Test.Case</code> constructor and pass in an object literal containing information about the tests to be run:</p>

```

Y.example.test.AsyncTestCase = new Y.Test.Case({

//name of the test case - if not provided, one is auto-generated

name : "Asynchronous Tests",

//---------------------------------------------------------------------

// setUp and tearDown methods - optional

//---------------------------------------------------------------------

/*

* Sets up data that is needed by each test.

*/

setUp : function () {

this.data = {

name: "test",

year: 2007,

beta: true

};

},

/*

* Cleans up everything that was created by setUp().

*/

tearDown : function () {

delete this.data;

},

//---------------------------------------------------------------------

// Test methods - names must begin with "test"

//---------------------------------------------------------------------

testWait : function (){

var Assert = Y.Assert;

//do some assertions now

Assert.isTrue(this.data.beta);

Assert.isNumber(this.data.year);

//wait five seconds and do some more

this.wait(function(){

Assert.isString(this.data.name);

}, 5000);

}

});

```

<p>The object literal passed into the constructor contains two different sections. The first section contains the <code>name</code> property,

which is used to determine which <code>Y.Test.Case</code> is being executed. A name is necessary, so one is generated if it isn't specified.</p>

<p>Next, the <code>setUp()</code> and <code>tearDown()</code> methods are included. The <code>setUp()</code> method is used in a <code>Y.Test.Case</code>

to set up data that may be needed for tests to be completed. This method is called immediately before each test is executed. For this example,

<code>setUp()</code> creates a data object. The <code>tearDown()</code> is responsible for undoing what was done in <code>setUp()</code>. It is

run immediately after each test is run and, in this case, deletes the data object that was created by <code>setUp</code>. These methods are optional.</p>

<p>The second section contains the actual tests to be run. The only test is <code>testWait()</code>, which demonstrates using

the <code>wait()</code> method to delay test execution. There are two arguments passed in: a function to run once the test resumes

and the number of milliseconds to wait before running this function (same basic format as <code>setTimeout()</code>). When

the test resumes, the function is executed in the context of the <code>Y.Test.Case</code> object, meaning that it still has

access to all of the same data as the test that called <code>wait()</code>, including properties and methods on the <code>Y.Test.Case</code>

itself. This example shows the anonymous function using both the <code>Y.Assert</code> object and the <code>data</code> property

of the <code>Y.Test.Case</code>.</p>

<h3>Running the tests</h3>

<p>With all of the tests defined, the last step is to run them:</p>

```

//create the console

var r = new Y.Console({

verbose : true,

newestOnTop : false

});

r.render('#testLogger');

//add the test suite to the runner's queue

Y.Test.Runner.add(Y.example.test.AsyncTestCase);

//run the tests

Y.Test.Runner.run();

```

<p>Before running the tests, it's necessary to create a <code>Y.Console</code> object to display the results (otherwise the tests would run

but you wouldn't see the results). After that, the <code>Y.Test.Runner</code> is loaded with the <code>Y.Test.Case</code> object by calling

<code>add()</code> (any number of <code>Y.Test.Case</code> and <code>TestSuite</code> objects can be added to a <code>TestRunner</code>,

this example only adds one for simplicity). The very last step is to call <code>run()</code>, which begins executing the tests in its

queue and displays the results in the <code>Y.Console</code>.</p>

<h2>Complete Example Source</h2>

```

{{>test-async-test-source}}

```